In large commercial bakeries there exist machines that mix ingredients to produce dough or mixed materials for baked goods such as bread, rolls, pizza, pastry etc. The larger designs of these machines have an elevated bowl where the materials are mixed. This larger design allows for removal of the dough by rotation of the bowl about a horizontal axis. The final height of the mixer""s bowl(s) lower edge is typically 2 to 4 feet above the ground.
The discharged mixed material must then be moved to machines or points for further processing and eventual production into a final product. Standard procedure is to either directly discharge the dough into the next processing machine or to transport the dough to the next processing machine. Transport can be accomplished by discharge of the mixed materials into a wheeled container, which is then moved to the required machine or location where it is hoisted and discharged or metered into the processing machinery. Another method of transport is to discharge the mixed material into a machine which will transport this mixed material to the required processing machine. Transport of the mixed material is usually accomplished by pumping it through pipes or metering it out and transporting it by conveyors. Typically the type of transport is determined by are typically the characteristics of the material. Fluid materials such as creme fillings or jams are moved by wheeled container or by pumping. More viscous materials such as dough products are typically moved by wheeled containers or by an auger metering it and then transporting it by conveyor.
The transport by wheeled container is typically the most labour intensive. With batch sizes approaching 4000 pounds per mix, the risk of personel strains or injury is high. A relatively new and commercially successful method of automatically transporting mixed materials is to meter the mixed material through a pair of counter rotating cutting rotors which produce a log shaped strip of material which can then be conveyed to the required destination. This works well with materials which do not adhere to the rotors. However, problems occur with certain types of materials which are soft and sticky. In these cases, the material often does not release off of the rotors and the rotors become clogged and passage of the material stops. Examples of these materials are Oatmeal Raisin and Macaroon cookie dough which have both high fat and sugar content.
To maintain operation of these machines a method and machine are required that will keep the materials from adhering to the rotors. Methods presently in use include using non stick or low adhesion coatings such as teflon on the rotors, and continuous or pulse spray coating application of release agents, such as oils and or lecithin.
The apparatus and method described here in are a mechanical solution where the rotors are stripped of dough by the wiping action of a wiper, preferably a wiper rod and/or scraper, which passes down the length of the rotors.
The invention is a mechanical means of stripping mixed materials, typically cookie dough from the cutting rotors of automated mixed ingredient handling machinery. Here specifically, the preferred embodiment of the invention comprises a scrapping or stripping device driven parallel to the axis of the rotors and along the surfaces of the cutting or metering rotors to cause the adhering mixed material to drop to a discharging conveyor.
Use of described invention would allow for removal of adhering dough material to rotors of typical dough handling machines.
Use of described invention would provide consistant stripping of adhesive dough materials from the surfaces of the cutting rotors.
Use of wiper bar wound wipe materials that would adhere to the rotors and cause them to drop onto a conveyor located below.
Use of wiper bar would maintain material flow.
Wiper bar/scraper is a unique way to keep rotors unclogged.
Wiper bar and travel thereof are unique and allows rotors to be cleaned and maintain material flow.
Operation of wiper bar/scraper not restricted to use of given or illustrated example drive systems.
A mixed material handling machine typically operates by having a hopper with two matching rotors in the bottom of the hopper. These rotors counter rotate thereby entraining mixed material within the cavities of the rotors as seen in FIG. 1. The diameter of the rotors and the open area between the blades of the rotors determining the amount of dough that may be entrained per revolution. The rotation of these rotors being intermittent. Upon the start of the cutting or metering cycle the rotors will rotate until two matching blades come together to pinch off the metered amount of material from the material contained within the hopper above the rotors. Typically when the rotors reach the point where the two mating blades form a straight line to each other the gravitational force pulling the metered amount of material will be sufficient to cause the metered amount of material to pull away from the surface of the rotors and fall to the conveyor below.
However with high adhesion doughs or mixed materials, such as oatmeal raisin, two possibilities may arise to prevent the dough from pulling away from the rotors. First, the high adhesion may prevent the dough from releasing and the dough then stays on the rotor(s). Second, the low tensile strength or low cohesive nature of the dough allows part of the dough to adhere to the rotors with only part or portions of the dough dropping to the discharge conveyor. With either case the rate of dough deposit results in a subsequent transportation decrease to below what is required by the processing machinery. The condition may progress to where the rotors become totally clogged and all dough passage effectively stops.
To prevent the clogging condition in the instant invention a wiper, preferably a wiper rod, is shaped to the contour of the rotor faces and driven the length of the rotors on a path parallel to the rotational axis of the rotors.